1. Field of the Invention
The present invention relates to an ink-jet head and, more particularly, to an ink-jet head used for generating droplets of ink for a so-called "ink-jet recording system", and further relates to a method for fabrication thereof.
2. Description of the Prior Art
An ink-jet head which is adopted in ink-jet recording systems is generally provided with a fine ink discharging port (or orifice), an ink flow path, and elements for generating an ink discharging pressure arranged in the ink flow path. Heretofore, there have been known various methods for fabricating ink-jet heads, for example, a method comprising shaping fine grooves on a plate of glass or metal by cutting or etching and then bonding or pressing the plate thus processed to another appropriate plate to form ink flow paths.
Ink-jet heads produced by the conventional methods suffer from the following drawbacks. An ink flow path having a constant resistance to ink flowing is difficult to obtain due to roughness of the interior wall surface of the ink flow path when it is fabricated by cutting, or due to nonuniform flow paths which are formed due to the difference in the etching rate. Consequently, ink-jet properties of the resulting ink-jet head would be varied.
Also in the cutting process, the plate is liable to be broken or cracked resulting in lowering of the production yield, and in the etching process many steps are disadvantageously required resulting in a high production cost. In addition, the above mentioned conventional methods suffer from drawbacks such as positioning of a grooved plate and a lid plate provided with a driving element, generating energy for actuating the ink such as a piezoelectric element, an exothermic element and the like, is very difficult resulting in a low rate of mass production. The ink-jet head according to the aforesaid known process has a critical drawback such as straight driving of ink droplets is hindered. This drawback mostly results from a difference in absorbability of materials of which the ink-jet head nozzle is composed.
Heretofore, in order to remove these drawbacks it has been proposed that an orifice plate made of a homogeneous material is separately formed and is assembled with a head-body. This process, however, disadvantageously requires adhesives, which are liable to flow into fine ink nozzles or fine ink flow paths. This results in clogging of the nozzles which deteriorates the ink-jet head.